1. Field of the Invention
This invention relates to power transmission belts and, more particularly, to a power transmission belt having at least one rib with a longitudinal groove formed therein that reduces noise accompanying the running of the belt.
2. Background Art
V-belts and V-ribbed belts are used in a wide range of environments. V-ribbed belts are preferred for their high power transmission capability, which is attributable to the large in contact area between the ribs on the belt and the flank on the cooperating pulleys.
In operation, there is a tendency for V-belts and V-ribbed belts to emit noise; a common complaint, especially on automotive drives. Belt noise is predominately the result of pulley engagement and disengagement noise arising as the ribs on the belt enter into and exit from the pulley grooves or arising from excessive rotational slip of the pulley relative to the belt. Rotational slip occurs during rapid acceleration or deceleration of the drive such as is encountered during shifting, engine startup or engine shutdown or due to excessive loading or insufficient wrapping around the pulleys.
Previous attempts to reduce belt noise have utilized materials substitutions and have focused on interfacial characteristics between the pulley and the belt flanks without affecting the forces normal to the belt flanks.